Use of bait containing triclabendazole against Fasciola gigantica in a herd of captive wild impala (Aepyceros melampus).

Although the efficacy of triclabendazole treatment against Fasciola gigantica has been shown before in cattle and buffaloes, there appears to be no published report on the efficacy of triclabendazole in impala or other antelope species. As part of a health monitoring programme at Mulungushi International Conference Centre, Lusaka, Zambia, a coprological examination was undertaken to investigate the helminthological status of captive impala (Aepyceros melampus). Of 39 fresh coprological samples, 46% contained F. gigantica. The source of infection was identified to be a fountain within the grounds of the conference centre. Lymnaea natalensis, collected from the study site, were induced to shed cercariae, and were thus confirmed as the snail intermediate host. In managing this disease, triclabendazole at 6 mg/kg was administered together with the feed bait. Water from the pond was drained; vegetation within it cleared and the pond allowed to dry for 1 week before water was replaced. Three weeks post-treatment, faecal examination revealed that the Fasciola had been cleared. To the best of our knowledge, this is a first case of Fasciola spp. infection reported in captive wild impala in Zambia and provides evidence that triclabendazole may be delivered to free-ranging antelope using medicated bait.

Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis.

Faecal samples were collected from the rectum of 540 domestic dogs from four districts (Lusaka, Katete, Petauke and Luangwa) in Zambia between 2005 and 2006 and prevalences of canine alimentary tract parasites were determined by coprological examination. Thirteen different ova and parasites including strongyle (43.3%), Spirocerca lupi (18.7%), taeniid (13.1%), Toxocara canis (7.6%), Sarcocystis sp.* (7.5%), Isospora sp.* (5.7%), Physaloptera sp.* (4.6%), Capillaria sp.* (2.8%), Dipylidium caninum (2.2%), Mesocestoides sp.* (2.0%), Ascaris sp.* (1.7%), Trichuris vulpis* (0.4%) and Schistosoma mansoni* (0.4%) were detected, Ascaris and Schistosoma probably originating from coprophagy. The species with asterisks and later-described Taenia multiceps are for the first time reported from dogs in Zambia. A coproantigen enzyme-linked immunosorbent assay (CoproAg-ELISA) developed for Echinococcus spp. revealed 43 positive dogs and 37 of these harboured taeniid eggs. From 63 of the 71 taeniid egg-positive samples, eggs and DNA thereof were isolated and subjected to a multiplex polymerase chain reaction for differentiating E. granulosus sensu lato, E. multilocularis and Taenia spp. Amplicons indicative for Taenia spp. were obtained from 60 samples. Sequencing of amplicons spanning part of the mitochondrial cytochrome c oxidase subunit 1 gene, which was possible with 38 samples, revealed 35 infections with T. hydatigena and 3 with T. multiceps. Therefore, the CoproAg-ELISA showed some positives, but concrete evidence for the existence of canine E. granulosus infection could not be established. Comparison of the results of the CoproAg-ELISA and Taenia species identification indicated that the CoproAg-ELISA cross-reacts with patent infections of T. hydatigena (57%) and T. multiceps (33%).

Prevalence of bovine tuberculosis and animal level risk factors for indigenous cattle under different grazing strategies in the livestock/wildlife interface areas of Zambia.

A cross-sectional study was conducted to investigate the prevalence and animal level risk factors for bovine tuberculosis (BTB) in indigenous cattle of the livestock/wildlife interface areas in Zambia. A total of 944 cattle from 111 herds were investigated. The comparative intradermal tuberculin test (CIDT) was used to identify reactor animals for BTB. Animal level data on sex, age, parity and body condition score were registered. The overall animal prevalence of BTB as determined by the CIDT was 6.8% (95% CI: 4.2, 9.5%). In Lochinvar and Blue Lagoon areas, animal level prevalence were observed at 5.2% (95% CI: 2.2, 8.2%) and 9.6% (95% CI: 6.1, 13.2%), respectively. Kazungula, an area outside the livestock/wildlife interface, had a prevalence of only 0.8% (95% CI: 0.0, 2.3%). The age of the animal, its body condition score and the type of management system, were predictive of its BTB status. The study revealed that BTB was relatively high in the livestock/wildlife interface areas of Lochinvar and Blue Lagoon compared to Kazungula. These findings should raise a serious public health concern considering the extent to which the communities of the study areas are in contact with their animals and the levels at which they use untreated milk.

Risk factors associated with bovine tuberculosis in traditional cattle of the livestock/wildlife interface areas in the Kafue basin of Zambia.

We conducted a cross-sectional study from August 2003 to February 2004 to identify risk factors for bovine tuberculosis (BTB) in the Kafue basin of Zambia. We investigated a total of 106 herds of cattle for presence of BTB using the comparative intradermal tuberculin test (CITT) while an interviewer-administered questionnaire was used to gather epidemiological data on herd structure, management and grazing strategies. BTB prevalence at herd level was estimated and possible risk factors were investigated using the multiple logistic regression model. The true herd level prevalence of BTB was estimated at 49.8% (95% CI: 37.9, 61.7%). The logistic regression model showed that cattle herd BTB status was highly associated with area and husbandry practices. When compared to Kazungula, cattle herds in Blue Lagoon were more likely to test positive for BTB when other factors such as management practices were controlled (OR=10.5). In terms of grazing strategies, transhumant herds (TH) had higher odds (OR=3.0) of being positive compared to sedentary herds (OR=1.0). The results in this study provide preliminary information about potential risk factors that were found to be associated with BTB status in cattle.

Prevalence and genotyping of Cryptosporidium in three cattle husbandry systems in Zambia.

To estimate the prevalence of Cryptosporidium spp. in three different husbandry systems in Zambia, faecal samples were collected from calves up to the age of 3 months. Faecal consistency was scored for correlation with infection. Additionally, 45 positive samples were selected for genotyping by amplification of the 70-kDa heat shock protein (HSP-70) and the 18S rRNA gene. A total of 37 dairy, 25 beef and 92 traditional husbandry farms were visited: 250 samples were collected on dairy farms, 238 on beef farms and 256 on traditional husbandry farms. All samples were analysed using a commercial copro-antigen ELISA (Techlab)(Cryptospridium test). The calf prevalence in dairy, beef and traditional husbandry systems was 42.8%, 8.0% and 6.3%, respectively. Furthermore, 75.7% of the dairy farms, 44.0% of the beef farms and 15.2% of the traditional husbandry farms had at least one positive calf at the time of visit. Subsequently, there was a significantly higher Cryptosporidium parvum prevalence on dairy farms compared to beef or traditional farms (chi(2), P<0.001). On dairy farms low faecal consistency was correlated with C. parvum infection (chi(2), P<0.05). Both C. parvum and C. bovis were identified, although in one beef calf C. suis was found.